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  • 1
    Electronic Resource
    Electronic Resource
    Source spectra and RMS acceleration of Mexican subduction zone earthquakes (1990)
    Springer
    Pure and applied geophysics 133 (1990), S. 447-474 
    Details
    ISSN: 1420-9136
    Keywords: Source spectra ; RMS acceleration ; Mexican earthquakes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Strong motion (SM) data of six Mexican subduction zone earthquakes (6.4≤M S≤8.1) recorded near the epicentral zone are analyzed to estimate their far-field source acceleration spectra at higher frequencies (f≥0.3 Hz). Apart from the usual corrections such as geometrical spreading (1/R), average radiation pattern (0.6), free surface amplification (a factor of 2), and equal partitioning of the energy into two orthogonal horizontal components (a factor of 1/ $$\sqrt 2 $$ ), the observed spectra are corrected for a frequency dependentQ(Q=100f), a site dependent filter (e −πkf ), and amplification ofS waves near the surface (a factor of about 2 atf≥2Hz). We takeR as the average distance from the rupture area to the site. If we model the high frequency plateau (f≥1 Hz) of the source spectra, by a point source ω−2-model, and interpret them in terms of Brune's model we obtain δσ between 50 and 100 bars for all earthquakes. The low-frequency broadband teleseismicP wave spectra, corrected witht *=1.0 s, agrees within a factor of two with SM source spectra near 1 Hz. The ω−2-model is inadequate to explain the observed source spectra in a broad frequency range; these resemble spectra given byGusev (1983) with some differences. SM source acceleration spectra require significant corrections to explain observed spectra and RMS acceleration (arms) (a) at farther coastal sites for extended sources due to directivity effect and (b) at inland sites (100≤R≤200 km) because of unaccounted path and site amplification and/or invalidity of body-wave approximation. The observed spectra and arms at these sites are significantly greater than the predicted values from the estimated source spectra.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00878000
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  • 2
    Electronic Resource
    Electronic Resource
    A unified approach to systematic isosteric substitution for acidic groups and application to NMDA antagonists related to 2-amino-7-phosphonoheptanoate (1990)
    s.l. : American Chemical Society
    Journal of medicinal chemistry 33 (1990), S. 1077-1083 
    Details
    ISSN: 1520-4804
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/jm00165a030
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  • 3
    Electronic Resource
    Electronic Resource
    Ab Initio Study of Electronic Structure and Jahn-Teller Effect of Tetrachloromethane Cation (1995)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 99 (1995), S. 12135-12140 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/j100032a014
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  • 4
    Electronic Resource
    Electronic Resource
    Identification of Synapse Specific Components: Synaptic Glycoproteins, Proteins, and Transmitter Binding Sites (1981)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 37 (1981), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: Synaptic junctions (SJ) were prepared from synaptic plasma membranes (SPM) by extraction with Triton X-100 and density gradient centrifugation. These SJs were enriched in certain Concanavalin A (Con A) binding glycoproteins, the 52,000 Mr postsynaptic density (PSD) protein, and receptor sites for l-glutamate, l-aspartate, kainic acid (KA) but not quinuclidinyl benzilate (QNB). Various other membrane fractions were extracted by means of the same procedure. Those fractions prepared from light SPMs and crude myelin contained identifiable synaptic junctions and were also highly enriched in the synaptic components. The SJ-like fraction from mitochondria did not contain any of the characteristic synaptic macromolecules. However, this fraction from microsomes contained levels of the 52,000 Mr PSD protein and binding sites for l-glutamate (l-GlU) and l-aspartate (l-Asp) similar to true synaptic junctions, although the Con A binding glycoproteins and KA binding sites were nearly absent. On the basis of electron microscopy, the SJ-like fraction from microsomes did not contain structures recognizable as SJs. Thus, the Con A binding glycoproteins and KA binding sites appear to be excellent markers for the SJ.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-4159.1981.tb06327.x
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  • 5
    Electronic Resource
    Electronic Resource
    Characterization of L-Glutamate Binding Sites in Rat Spinal Cord Synaptic Membranes: Evidence for Multiple Chloride Ion-Dependent Sites (1986)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 47 (1986), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract The effects of various ions on L-glutamate (L-Glu) binding sites (Na+-dependent, Cl−-dependent, and CP−-independent) in synaptic plasma membranes (SPM) isolated from rat spinal cord and forebrain were examined. CP−-de-pendent binding sites were over twofold higher in spinal cord (Bmax= 152 ± 34 pmol/mg protein) as compared to forebrain SPM (Bmax= 64 ± 12 pmol/mg protein). Na+ dependent binding, on the other hand, was nearly sixfold less in spinal cord (Bmax= 74 ± 10 pmol/mg protein) compared to forebrain SPM (408 ± 26 pmol/mg protein). Uptake of L-Glu (Na+-dependent) was also eightfold less in the P2 fraction from spinal cord relative to forebrain (Vmax of 2.89 and 22.3 pmol/mg protein/min, respectively). The effects of Na+, K+, NH4+, and Ca2+ on L-Glu binding sites were similar in both regions of the CNS. In addition, in spinal cord membranes, Br−, I−, and NO3− were equivalent to C− in their capacity to stimulate L-Glu binding, whereas F−and CO32− were less effective. Cl−-dependent l-Glu binding in spinal cord membranes consisted of two distinct sites. The predominant site (74% of the total) had characteristics similar to the Cl−-dependent binding site in forebrain membranes [i.e., Ki values of 5.7 ± 1.4 μM and 119 ± 38 nM for 2-amino-4-phosphonobutyric acid (AP4) and quisqualic acid, (QUIS), respectively]. The other CP-dependent site was unaffected by AP4 but was blocked by QUIS (Ki= 14.2 ± 4.8 μM).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-4159.1986.tb00719.x
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  • 6
    Electronic Resource
    Electronic Resource
    Solvatochromism of a typical merocyanine: stilbazolium betaine and its 2,6-di-tert-butyl derivative (1992)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 96 (1992), S. 3615-3621 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/j100188a013
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  • 7
    Electronic Resource
    Electronic Resource
    Evidence for anomalous body-wave radiation between 0.3 and 0.7 Hz from the 1985 September 19 Michoacan, Mexico earthquake (1990)
    Oxford, UK : Blackwell Publishing Ltd
    Geophysical journal international 101 (1990), S. 0 
    Details
    ISSN: 1365-246X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: In order to better understand the causes of unprecedented damage to Mexico City during the 1985 September 19 Michoacan earthquake (Mw= 8.0) spectral ratios of teleseismic P-waves of this earthquake are studied with respect to those from five recent, large Mexican subduction zone earthquakes (7.0 ≤Mw≤ 7.7). The data are from vertical-component digital seismographs. It is found that the spectral ratios at stations in the NE quadrant are anomalously more energetic than those predicted by the ω−2 source model in the critical frequency range for Mexico City (0.3-0.7 Hz). The evidence is especially convincing for the spectral ratios with respect to the earthquakes of 1985 September 21 (Mw= 7.6) and 1986 (Mw= 7.0) since the data are available from several stations in the NE quadrant. The teleseismic P-wave spectral ratio in this quadrant with respect to the 1985 September 21 earthquake, in the critical frequency range, is close to the acceleration spectral ratio found in and near Mexico City (also in the NE quadrant). Velocity traces in the epicentral region of the Michoacan earthquake, obtained by integrating the accelerograms, also show oscillations with a frequency of about 0.4 Hz. Furthermore, a regression study of Fourier acceleration spectra at a hill-zone site in Mexico City demonstrates that the Michoacan earthquake was anomalously energetic in the city at the critical frequencies for an event of that magnitude and at that distance. If the data from 7.0 ≤Mw≤ 7.7 events can be extrapolated to estimate the ground motions from Mw≥ 8.0 earthquakes, then the evidence, supports an anomalously large body-wave radiation towards Mexico City between 0.3 and 0.7 Hz during the Michoacan earthquake. This anomalous radiation and the dramatic local amplification of seismic waves in the lake-bed zone of the city (∼ 10–50 times at frequencies between 0.3 and 0.7 Hz) appear to be the principal natural causes of the disaster. The anomalous teleseismic P-wave spectral ratios with respect to the earthquakes of 1985 September 21 and 1986 found in the NE quadrant are not observed in the data available from a small number of stations in the other quadrants. If this observation is true then it suggests a directional property to the anomalous radiation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-246X.1990.tb00756.x
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  • 8
    Electronic Resource
    Electronic Resource
    Synaptic localization of kainic acid binding sites (1981)
    [s.l.] : Nature Publishing Group
    Nature 289 (1981), S. 73-75 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Synaptic junctions (SJs) and other subcellular fractions were prepared by the method of Cotman and Taylor11, and assayed for 3H-KA binding12,13. Table 1 shows the relative values for specific binding (the 3H-KA binding which can be displaced by 100 µM unlabelled KA) in the isolated fractions, ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/289073a0
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  • 9
    Electronic Resource
    Electronic Resource
    High-Affinity [3H]THA (Tetrahydroaminoacridine) Binding Sites in Rat Brain (1991)
    Springer
    Pharmaceutical research 8 (1991), S. 200-203 
    Details
    ISSN: 1573-904X
    Keywords: tetrahydroaminoacridine (THA) ; THA binding sites ; Alzheimer’s disease ; acetylcholinesterase inhibitors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Tetrahydroaminoacridine (THA), an acetylcholinesterase inhibitor that is reported to have significant effects on cognition and memory in Alzheimer’s disease patients, binds to rat brain membranes in a saturable and reversible manner. Computer analysis of the binding data revealed high- and low-affinity sites with K d values of 97.8 nM and 4.65 µM and B max values of 4.13 and 114 pmol/mg protein. Autoradiographic studies show that these binding sites are not co-localized with acetylcholinesterase activity. The binding of [3H]THA to membranes does not appear to be related to receptors for several neurotransmitters/neuromodulators, including acetylcholine and other acetylcholinesterase inhibitors. Amiridin, a closely related acetylcholinesterase inhibitor, was able to block specific [3H]THA binding (IC50 = 1.05 µM). While the function of THA mediated by these sites is unknown, they may be responsible in part for the distinct clinical effects of tetrahydroaminoacridine compared to other acetylcholinesterase inhibitors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1015840003630
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